Blowpipe machine



y 1942- J. H. BUCKNAM ETAL 2,283,346

' BLOWPIPE MACHINE Filed April 26, 1940 '2 Sheets- Sheet 1 I lNVEbiTORS Lw'vAMJ JAMES H. BUCKNAM v LLOYD W YOUNG ATTORNEY' May 19, 1942. J. H. BUCKNAM ETAL 2,283,346

BLOWPIPE MACHINE Filed Aprii 26, 1940 2 Sheets-Sheet 2 'INVENTORS JAMES H. BUCKNAM LLOYD W.Y.OU.NG

ATTRE Patent ed May 19,1942

BLOWPIPE MACHINE James H. Bucknam, Cranford, and Lloyd W. Y Young, Scotch Plains, N. 1., asslgnors to Orweld Acetylene Company, a

corporation of West Application April as, 1940, Serial No. 331,694.

15 Claims. (cl. ass-2s) This invention relates to blowpipe machines, and more particularly to a machine for thermochemically cutting ferrous metal bodies such as steel bars and billets of various sizes and shapes.

Steel bars and billets have previously been cut by blowpipe machines which move an oxidizing gas jet transversely of the bar being cut at a suitable cutting speed. Such machines, however, were specially constructed for cutting bars of a particular shape and a machine for cutting round stock was not suitable for cutting rectangularjstock and vice versa. It was necessary to provide a special machine for each commercial application which has resulted in greater expense and-limited the use of this method of cutting bar stock.

The gas-cutting blowpipe has been found advantageous for cutting billets in steel mills particularly when it is desired to cut oil defective ends or to cut the billets into desiredlengths between rolling stages and after they have been inspected. Such billets are usually of various sizes and may be either round or rectangular according to the type of product the mill is rolling at any particular time. It is, therefore, desirable that the cutting device should be quickly adJust-. able for efilciently cutting a variety of sizes and shapes and also quickly adjustable or mountable with respect to billets at various locations in a iven area.

It is a principal object of the present invention to provide an improved machine for thermochemically severing ferrousmet'al steel bars and billets.

Other objects of the-invention are to provide an improved mechanism for moving, a cutting blowpipe with respect to a metal body-to be cut or operated on, which mechanism is readily adaptable to various sizes and types of metal bodies and which is adjustable to operate under various conditions: to provide such a mechanism which is quickly adjustable to operate on round or on rectangular bars and which is also readily adjustable to accommodate a substantial range provide a mechanism for cutting metal bars or billets with a gas-cutting blowpipe which may be installed adjacent a conveyor line that carries,

operation at a comfortable distance from such hot bars; and to provide such a mechanism which is relatively light, simple, andeconomical to manufacture.

The manner in which this invention atta these and other objects will be apparent from the following description and accompanying drawinss in which: Y J

Fig. l is an elevational view of a preferred form of blowpipe mechanism according to the inven-'. tion;

Fig. 2 is a-diagrammatic representation of the crank-driving mechanism in the machine;

Fig. 3 is 'a diagrammatic representation of an altemative arrangement of the hydraulic driving circuit employing a direction changing valve;-

Fig. 4 is an elevational viewed a modified forin I of the mechanism arranged for cutting round billets supported on a conveyor; s

Fig. 5 is another arrangement of means supporting the blowpipe mechanism for cutting rec- I T tangular billetsiand 1 Fig. 6 is still another arrangement of me chanism for supporting and moving the blowpipe mechanism so that it may be mounted on variousbillets on a floor. v

" Referring to Fig. l the blowpipe is shown at B and has at its lower end a cutting nozzle N.

' This blowpipe and nozzle may be of the cusbodies such as of different diameters and widths of bars; to 45,

tomary construction for producing a, cutting let surrounded by a series of heating flames. The

blowpipe is supplied with oxidizing gas and fuel gas through flexible conduits or hoses H connected to its upper endin'the customary manner. The blowpipe B is supportedby a holder N in which the blowpipe is vertically slidable.

In the holder is a pinion II which meshes with a rack I! secured along thefront of the blowpipe. The pinion ii is turnable by a handwheel ll lor adjusting the height of the blowpipe nozzle N with respectQto the work W which may be a cylindrical bar, as indicated by the broken lines. The

holder It "is centrally secured to the front side of a horizontal link II, the end portions of which are journaled on forwardly extending crank pins I! and II. The crank pins and II are se-' cured to crank pin blocks I! and It, respectlvely,. so that the pins are parallel to, each other and to.

'themain axis of the work. The pin blocks ill.

and I. are secured at the ends of a pair'of oscillatable crank arms I1 and I 'l'-, respectively, which are longitudinally adjustable in crank blocks-ll-.. audit. The crank blocks II and I! are secured to. the forwardly extending ends of two crank shafts it and W Tlie' crank shafts ll and I3 are parallel to the crankpins l3 and I3 and to the main axis of the work W. The crank shafts l3 and I3 are also horizontally at the same level and are spaced apart a distance which is the same as the distance between the crank pins l5 and IS. The crank arms l1 and H are offset to one side of the crank shafts I3 and i3 in order to provide adequate clearance for adjustment of the distance between the crank pins and the crank shafts through a relatively wide range.

To maintain the desired adjustment of the active length of the crank arms, there are provided set screws 23 and 23' which are threaded in the blocks I3 and I3, respectively, and the ends of which engage notches or drilled holes in the crank arms i1 and II. The crank block l3 may be fixedly secured to the crank shaft l3. However, in some instances as will be explained hereinafter, it may be desirable to permit the relative rotational movement between one of the blocks l3 or l3 and the respective crank shaft. The blocks l3 and I3 are, therefore, rotatably secured to the ends of the crank shafts and to lock the blocks to the crank shafts there are provided set screws 2| and 2|, the ends of which engage depressions-in the crank shafts l3 and IS. The crank shafts l3 and I3 are joumaled in bearings secured in the front and back walls of a rectangular box-like gear housing 22.

The arrangement of the crank-shaft driving mechanism is diagrammatically illustrated in Fig.2 andcomprises a pair of spur gears 23 and 23 of equal pitch and diameter which are keyed to the shafts l3 and I3, respectively. A rack 23 is disposed immediately under the gears 23 and 23' and arranged to mesh with both gears so that by horizontally moving the rack the crank is also provided a by-pass around the valve 32 connecting conduits 3| and 33 and controlled by a check valve 34. The check valve 34 is arranged to provide free flow of fluid from conduit 33 to inlet 29 and to prevent flow therethrough in the other direction. Another by-pass is arranged to connect conduit 3| with conduit 33 and is controlled by a back-pressure valve 35. The back-pressure valve 35 is arranged to pass liquid in either direction between conduits 30 and 3| and may comprise a customary type of back-pressure valve which may have therein a poppet type of valve element which is urged toward its seat by a spring, and lifted from its seat by a pressure responsive element and arranged so that the force of the spring may be adjusted as desired to cause the valve to open against the force of the spring only when the pressure on either side of the valve exceeds the set valve pressure, which value is suflicient to maintain a differential of pressure between conduits 30 and 3| that will move the piston 21 in the cylinder C with a suitable force. When the motor M is driven in the proper direction to cause oil to flow out through connection 23, the oil will freely circulate through the system in a clockwise direction through conduit 33 into the head end of the cylinder C, thus driving the piston 21 to the left at a relatively rapid rate. The oil on the rod side of the piston 21 will flow out through conduit 33 and through valves 32 and 33 .to connection 23, thus completing the circuit.

When the motor M is reversed, oil will be forced out connection 29 into conduit 3|. Valve 33 will remain closed to prevent flow therethrough and valve 32 will restrict the flow so that oil will flow to conduit 33 at a relatively slow'rate determined by the setting of the valve 32 which may be reshafts l3 and I3 will be simultaneously rotated rod 2'3 which is secured to the piston 21 of a hydraulic cylinder C. The rod end of the cylinder C is secured against and supported on the right-hand end of the housing 22, projecting horizontally therefrom.

Any suitable means for supplying fluid to the rod and head ends of the cylinder C may be employed. For example, liquid under pressure may i be supplied from an external source to either end .so as to move the piston and thereby move the blowpipe at the desired rate in either direction.

. A preferred arrangement for circulating a drivf ing fluid, such as oil, is illustrated in the draw- Such circulating means comprises a re-,

ings. versible electric motor M secured against the end of the housing 22 above. the cylinder C and a rotary pump Pv directly coupled .to the motor M, and supported on the frame of the motor. The

- pump P is preferably of a positive displacement reversible type such as a gear pump and is provided with-two fluid connections 23 and 23 either or which may serve as a fluid outlet, according to the direction of rotation of the motor. Connection 23 is preferably placed in communication with the head end of the cylinder C by a conduit 33. Connection 23 is placed in communication with the rod end of cylinder C through a conduit corded by an index 36. When the pressure in conduit 3| overcomes the valve 35, the oil that is pumped in excess of that passing valve 32 will flow through valve 35 to connection 23. The rate of movement of piston 21 is thus readily ad- Justable to move the nozzle N at a desired uniform cutting speed and a simple reversal of the motor M provides a quick return of the nozzle Ntto a starting position for beginning another on It will usually be desirable to limit the movement of the blowpipe in either direction so that the blowpipe nozzle can be positioned accurately with respect to the starting end of the kerf to be made. To this end there'is provided a pair of adjustable stop screws 31 and 31' axially in line with the rack 23, rod 23, and piston 21. The screw 31 is threadedly supported in the end wall of the housing 22 and limits motion of the blowpipe to the right by engaging the left end of the rack 23 and the screw 31' is threaded through the head of the cylinder C to engage the piston 1"Rand limit movement of the blowpipe to the In some instances it may be desired to supply the driving fluid from a source in a constant direction such as by a constantdirection pump P. A suitable alternative arrangement is illustrated diagrammatically by Fig. 3. The pump P is driven at a constant speed and direction I so that the fluid enters at 23' and is discharged 3|, a needle valve 32, and a conduit 3;, There in a clockwise direction communicates with conthrough a connection 42' with the conduit 3:. A

A unidirectional back-pressure valve 35' is connected between-the pump inlet and outlet conjusting valve '32. The flfth port communicates perature and then the operator will turn on the oxidizing gas with valve V and throw the switch of the motor M to rotate the pump in the direction that will force oil at the regulated rate into the rod end of the cylinder duits 3| and 40. When the valve element 39 is in the counterclockwise position shown, the fluid discharged at 28' flows. through conduit 40,

through the valve passa e 43 of the valve element 39to the conduit 30 and from the conduit 33 through connection 42 and a passage 44 of the valve element to conduit 3| and inlet 29. This drives the piston 21 rapidly to the left, moving'the blowpipe to the right. To reverse the movement, the valve element 39 is moved clockwise about V of a turn to cause the passage 44 to connect conduit 3| with conduit 30 and the passage 43 to connect conduit 45.! with conduit 4!. Connection 52 will be blanked off. The flow will then be from outlet 28 through conduit 40, connection 43, conduit 5!, valve 32, and conduit 33 to the rod end of the cylinder, and from conduit 30, connection 6%, conduit 3!,to inlet 29'. The piston will then move to the right at a speed controlled by valve 32 and any excess fluid pumped will be try-passed by back-pressure valve 35' which may be of a more simple form since the flow therethrough will always be in the direction from conduit 3! to conduit so. A two I directional back-pressure valve 35 is desirable in the form of apparatus in Fig. 1 because the pump will then not be stalled when the piston reaches. either limit of travel.

Referring to Fig. 4, the work W'is shown supported upon rollers 55 of a conveyor. At one side of the line of conveyor rollers 45, the blowpipedrhiing mechanism A is mounted at a suitable height on a column 56 which may be disposed 'at a sufficient distance from the conveyor line so that the heat of a hot billet will not adversely I affect the mechanism A and so that an operator may operate the apparatus from a position ad- .jacent the mechanism A. In place of'the link it there is substituted an extended arm 61 which is journaled adjacent its right-hand endto the C, thus driving the nozzle N transversely across the work W in a path parallel to the work surface and at the proper cutting speed. When the nozzle reaches the far edge of the work and the billet is completely severed, the operator will shut off the gases and throw the motor switch to cause the blowpipe B to be returned to the 1 starting position at. a relatively high speed in of the gear box 22.

preparation for making another cut.

An alternative form of mechanism for supporting the blowpipe-moving mechanism A is illustrated in Fig. 5 which shows a carriage 55 similar to that of an overhead cranewhich is mounted to travel along rails 5| supported on suitable foundation and arranged parallel to thelongitudinal axis of the work W. The work W may be a rectangular billet supported anywhere between rails 5| on a floor preferably on transverse bars 52. The carriage carries a hanger 53 which is transversely movable alonga transverse beam of, the carriage 50. The blowpipe mechanism A is suspended from the hanger end 55 pivotally connected to the hanger 53 and its piston rod 56 pivotally secured. to .the top ably controlled by an air valve 51 which receives a supply ofair from an external source through a hose 58 and which allows the passage of such.compressed air into the rod end of the cylinder when the valve 51 is in the upper position. When the handle of valve 51 is in the lower position, the air will be released from the rod end of the cylinder 54 which will allow the 1 mechanism A to be lowered into contact with crank pins I5 and I5 and which carries at its -.ing rod 48 which extends parallel to the arm' 41 and has an operating handle 49 near the mechanism A. The gas conduits H leading to'the upper end of the blowpipe B are also preferably the top of the work W. For cutting a rectangu-.

lar bar, the blowpipe mechanism A is provided -with a base 59 which has a flange 60 at one side for contacting the edge of the workW' when the mechanism A- is accurately centered over the work. The position of the flange 50 is 'adjustable with respect to the base 59 so that it may be adjusted for use on a wide variety of widths of work. a

For-properly moving the blowpipe B with respect to the rectangular bar W, the crank pins which are closer together by a definite amount provided with control valves located adjacent I the mechanism A.

To operate this embodiment according to the invention for cutting a hot bar W, the operator will throw a reversing switch to rotate the motor and pump P in the direction for quickly moving the arm 51 to the right. By turning handle 49, the operator may then adjust the height of the nozzle N. Previous to this, the length of the crank arms I! and II will have been adjusted to equal the radius of the bar W plus about inch which represents the desired spacing of the nozzle from the work surface. The operator will then open the valves V which control the: preheating gas-supply conduits and the preheating gases will ignite upon issuing from ,the nozzle N due to the heat of the billet T W. The heating flames will raise a spot on 75 than )the center to center distance of the crank shafts I9 and I9; such holes are shown at 5! and 5! in Fig. 1.

spacing and by providing the correct height of base 59 and length of blowpipe B, the end of the nozzle N will be caused to move in a substantially,

straight horizontal path at a substantially uniform distance" from the surface of the work W when the crankshafts I9 and I9 are rotated. When cutting square bars it will be necessary to loosen one of the set screws 2| or 2| to allow one, of the crank arms or H to move at a slightly different rate than the other crank arm. The principles of the crank and link, arrangement for cutting rectangular bars are more fully described in the copending application of L. W. Young, Serial No.'331,693.

To operate the. mechanism as, illustrated in Fig. 5, it will be assumed that the blowpipe mechani'sm is adjusted for cutting rectangular bars, that the length of the crank arms l1 and The cylinder 54 is prefer- By providing this closer I J then be-pushed laterally so that the hanger 53 mentioned copending application.

A. The mechanism A is provided with a base 68 having a V-shaped bottom surface 69 adapted to- 45 P p, a motor. connected to drive said pump,-

' and passage means connecting said pump. with;

1 described herein and illustrated in the accom; e5

- Other forms, diifering in detail but not in principle, will of course suggest themselves-to those I comprises a cutting blowpipe having a nozzle;

motor M or fluid flow'reversed to return the nozzle to a starting position, and 'the handle of will be obvious from the description of the opercan readily be mounted on anybar W that is I1 is adjusted, according to the width of the par W to be cut, that the flange I is positioned on the base 59 according to the width of the work W, and that the nozzle N is in its rightward porting and moving said holder to move said blowpipe ,in'a fixed plane extending transversely of the work to be out while moving said nozzle in a path which substantially follows the contour position. The operator will lift valve 51 allow-' 6 of the work surface; said mechanism comprising ing air to enter the rod end of cylinder 54 .and raise the mechanism A. The mechanism may a pair of-crank arms swingable about parallel axes; a link connecting said crank arms and v carrying said holder, thelength of said link will roll along the carriage 50 until the mechabeing adjustable to change the angular relation nism A is properly positioned over the billet W. 10 between said crank arms; gears of equal diam- The operator will then lower the handle of valve eter operatively connectible with' each crank 51 to lower the base 59 onto the work W. The arm; a rack meshing with both of said gears; operator after adjusting the position of the nozzle N with respect to the edge of thework W will ing said nozzle in said path; the arrangement turn on the'preheating gases which may be ignited is being such that, when said link is adjusted so by, for example, a pilot flame or by striking an that its length is equal to the distance between electric spark. When the corner is'sufliciently heated, the operator will turn on the oxidizing connected to said crank arms, movement of said gas and energize the motor M to turn the pump rack causes the mechanism tomove said nozzle P in the proper direction for moving the blowpipe 2 in an arcuate path to follow an arcuate work to the left at cutting speed. When the'bar W is surface, and, when said link is adjusted so that completely severed the gases may be shut off, the its length is less than the distance between said axes and only one of said gears is connected to its cra'nk arm, movement of said rack causes the valve 51 lifted to raise the mechanism A so that mechanism to move said nozzle in a flat'path to it can be moved over another billet to be cut. follow a flat work surfacei The bar will be completely severed by reason of 2 Blowpipe apparatus according to claim 1 in the angular position of the blowpipe at the flnhich said means for reciprocating said rack ishing endof the cut as explained in the afore comprises a cylinder, a piston in said cylinder 3 operatively connected with saidrack, means for supplying operating fluid at a. regulated relatively slow rate to said cylinder on one side of said piston to move said mechanism and the blowpipe in one direction for cutting work, and

Referring to Fig. 6 there is shown still another arrangement of apparatus for supporting the blowpipe mechanism A. The hanger 53 is arranged to roll along a boom 621 which is secured .at one end to a collar 83 rotatably secured to a me n f pp y n Operating fluid to said cylincolumn or mast 64. A tie rod 65 is secured to the outer end of the boom 82 and to another. collar 65 on the mast above the collar. In this form of the apparatus the housing 22 carries azhand rail 61 which encircles the. complete path of 40 which saidmeans for reciprocating said rack movement of the blowpipe B and forms a comprises a cylinder, a piston in said cylinder guard to prevent injury to the blowpipe as well operatively connected with said rack; and means as a convenient grip for moving the mechanism for moving said piston ineither direction comprising a closed hydraulic system including a der on the other side of said pistonat a relatively fast rate to eflfect a relatively quick return movement of said blow pipe.

contact with a cylindrical bar W and accurately center the mechanism A on such bar.

The operation of this form of. the apparatus saidcylinder at both sides of said piston.

atidn oi the previously described form of appacomprises a cylin er. a p o n S i ylinde ratus. Since, however, the mechanism A is operativelyflmnected with d ack; means for swingable with respect to the cylinder 54 about Supp y a pe at ng fluid under pressu a vertical center line, since the boom 82 is swing able about the mast l4, and since the mechanism valve mea s opera e o co t sa d flu d-sup- A is movable to any desired position along the to p meanslwlth said c i on either e of boom 62. itwillbe evident that the mechanism A Said piston and simultaneously to ect e. portion of said cylinder on the opposite 'side of the piston with said fluid receiving means, wher by in one position of said valve means the pis n and blowpipe will be moved in one direction an in the other position of said valve means the p ton and blowpipe will be moved in the opposite direction for cutting work.

, 5. Blowpipe apparatus according to claim 1 in which said means for-reciprocating said rack comprises a piston, a pump for operating said piston. and a motor for driving said pump, said motontand pump being reversible and arranged so tha the piston, mechanism, and blowpipe are mova e in either direction'desired according to the direction of movement ofsaid motor and pump.

6. Blowpipe apparatus according to claim 1 in supported on the floor in any position within the circle swept by the boom [2.-

Features of the apparatus shown in Fig; 5 and go of the apparatus shown in Fig. 6 are claimed in divisional application Serial No. 406,950, filed August 15, 1941, for Blowpip machine)? The particular embodiments of the invention pany drawings, are presented to indicate how the principles of 'the invention may be applied.

skilled in the art.

We claimi 1. Blowpipe apparatus adjustable for cuttin work of any desiredicroa-sectional shape, whi h a holder for said blowpipe; mechanism for sup' co ses a motor. d aul c means. including a and means for reciprocating said rack for mov-' said axes and both of said. gears are operatively.

3. Blowpipe apparatus according to claim in 4. Blowpipe apparatus according to claim 1 in which said means for reciprocating said rack means for receiving used operating fluid; and.

which said means for reciprocating said rackwhich said means for reciprocating said rack" comprises a motor, hydraulic means including a pump connected to said motor, a-cylinder, a piston connected to said rack, and hydraulic passage means connected between said pump and' said cylinder, said motor and pump operating in,a constant direction and said passage means having valve means therein operable to connect the outlet of said .pump alternately with either end portion of said cylinder and simultaneously to connect the opposite end portion of said cylinder with the inlet of said pump.

'8. Blowpipe apparatus adjustable for cutting work of any desired cross-sectional shape which apparatus comprises a cutting blowpipe having a nozzle; a holder for said blowpipe; mechanism for supporting and moving said holder to move said blowpipe in a fixed plane extending transversely of the work to be cut while moving said nozzle in a path which substantially follows the contour of the work surface, said mechanism comprising a pair of crank arms swingable about parallel axes, a link connecting said crank arms and carrying said holder, the operative length of said link being adjustable to changethe angular'relation between said -crank arms, the ar-' inder with a piston reciprocal therein, means c onnecting said piston to at least one of said crank arms for transmitting reciprocal movements of said piston to such arm to oscillate said crank 7 arms, and means for supplying an operating fluid at a desired rate to said cylinder on either side of said piston.

9. Blowpipe apparatus adjustable for cutting work of any desired cross-sectional shape which comprises a cutting blowpipe having a nozzle;

"a holder for said blowpipe; mechanism for supprising a pair of crank arms swingable about parallel axes, a link connecting said crank arms I 7 and carrying said holder, the operative length of said link'being adjustable to change the angular relation between said crank. arms, the arrangement being such that when said link is adjusted so that its operative length is equal to the distance between said axes, oscillation of said. crank arms moves said nozzle in an arcuate path for traversing an arcuate work surface, andwhen said link is adjusted so that'its operative length 75 is less than the distance between said axes, oscillation of said crank arms moves said nozzle in a substantially straight pathfor traversing a flat work surface; and mechanism for oscillating said crank arms comprising a gear operatively connected to one of said crank arms, a rack meshing with said gear, a cylinder with a piston therein connected to reciprocate said rack, means for supplying an operating fluid to said cylinder on either side of said piston to reciprocate said piston, and means for regulating the rate of movement of the blowpipe in one direction to a relatively low uniform rate for moving said blowpipe at a desired cutting speed and for regulating the rate of movement of the blowpipe in the other direction to a relatively high rate for effecting a quick return movement of said blowpipe.

10. Blowpipe apparatus for cutting hot bars and the like, which comprises a frame mounted in spacedpoperative relation to and at one side of a substantially horizontalbar to be cut; a pair of crank arms swingable in a substantially vertical plane about parallel substantially horizontal axes on said frame; a substantially horizontal link connecting said crank arms and having a portion extending beyond the .crank arms toward said bar, said portion being positioned above and transversely with respect to said bar; a cutting blowpipe; and a holder for said blowpipe secured'to said portion for supporting said blowpipe in an operative position with respect to said bar;said link and said crank arms being arranged so that said blowpipe will move parallel to itself in a substantially vertical plane transversely of the bar and in an arcuate path substantially equi-distant from the surface of said bar when said crank arms are moved through arcs. I

11. Blowpipe apparatus for cutting hot bars and the like, which comprises a frame mounted in spaced operative relation to and at one side of a horizontal bar to be out; said frame being substantially stationary with respect to said bar during the. cutting operation; a pair of crank arms swingable in a vertical plane about parallel horizontal axes on said frame; a horizontal link connecting said crank arms, and having a above and transversely with respect to said bar; a cutting blowpipe; a holder for said blowpipe secured to said portion of said link for supporting said blowpipe in'an operative position with respect to said bar; valve means mounted on said frame for controlling the gas delivered to said blowpipe; means mounted on said frame for driving said crank arms; means mounted on said frame for controlling said driving means; said link and said crank arms being arranged so that said blowpipe will move parallel to itself in a vertical plane transversely of the bar and' inan arcuate path substantially equi-distant from the surface of said bar when said crank arms are moved through arcs. v

12. Blowpipe apparatus comprising, in combination, a box-like housing containing a pair of blowpipe supporting crank shafts, a rack, gear means for translating longitudinal movement of said rackto simultaneous rotary movement of said shafts, andmeans for longitudinally moving said rack comprising a cylinder mounted on said housing containing a piston having a rod connected operating said p'iston,,and control means mounted on said housing for controlling the operation of said piston.

13. Blowpipe apparatus comprising, in combination, a box-like housing having substantially rectangular walls, a pair of parallel spaced crank shafts, bearings secured in the front and back walls of said housing-in which said crank shafts are journalled, a gear keyed to each of said crank shafts within said housing, a horizontal hydraulic cylinder mounted on an end wall of said housing, rollers mounted in said housing below said gears, a horizontal rack mounted on said rollers and meshing with said gears, a piston in said cylinder having a rod connected to'said rack, a blowpipe, means supporting said blowpipe including crank arms mounted on said crank shafts, a motor-pump unit mounted on said housing for operating said piston, and means for supplying gas to said blowpipe including valve means mounted on said housing. I, v e

l4. Blowpipe apparatus comprising, in combination, a blowpipe; a holder forsaid blowpipe;

and mechanism for supporting and moving said holder to move said blowpipe in a path spaced at fixed distance with respect to a work surface of any desired contour, such as arcuate or flat; said mechanism comprising a pairof crank arms swingable about parallel, axes: a link connecting said arms and carrying said holder; means for adjusting theJength of said link between said,

arms; crank blocks in which said arms are iongitudinally adjustable; crank shafts on which said blocks are rotatably mounted; set screws threaded to said crank blocks and ensaseable with said shafts for fixing each one ofsaid blocks againstrotation on its shaft: a pair of spur gears connected to said shafts; a rack meshing with both of said gears; and means for reciprocating said rack for moving said blowpipe in said path; the arrangement being such that, by

tightening both of said set screws, the length of said link may be adjusted to cause said blowpipe to move in a predetermined arcuate. path, and by.

loosening one of said set screws, the length of said link may be adjusted to cause the nozzle end of said blowpipe to move in a flat path.

l5. Blowpipe apparatus forcutting hot bars and the like, which comprises a frame adapted to be positioned inoperative relation at one side of a round bar to be out; a pair of-crank arms swingable in a plane transverse to the axis of said bar about parallel axes on said frame; a link in said plane pivotally connecting said crank arms at equal distances from said parallel axes, said link having a portion extending beyond said crank arms to a position over the surface of said bar; a cutting blowpipe; and a holder for said blowpipe on said portion for supporting said blowpip in said transverse plane and withvits main axis substantially perpendicular to said link in an operative position with respect to said surface of the bar, said link and said crank arms being arranged so that said blowpipe is maintained substantially parallel to its successive positions as it moves in said transverse plane in an arcuate path substantially equidistant from said surface of the bar when said crank armsare moved through arcs.

Jams n. sucxmu; morn w.. room. 

